Drawing instrument



H. L. READ, DEC'D. A. L. READ, ADMINISTRATRIX- DRAWING INSTRUMENT.

APPLICATION FILED FEB. 8.1919.

1,379,124. Patented May24, 1921.

1, III[IIIIIII'IIIIIIIIIIIIIIIIIIII'IIIII UNITED STATES raTsNT OFFICE.

HORACE L. READ, 0F QUINCY, WEST VRGINIA; ANNA L. READ ADMINISTRATRIX 0F SAID HORACE L.

READ, DECEASED.

DRAWING ENSTRUMENT.

Specification of Letters Patent.

Application led February 8, 1919. Serial No. 275,331.

To all whom t may concern.'

Be it known that l, HORACE L. Ranma citizen of the United States, residing at Quincy, in the county of Kanawha and State of West Virginia7 have invented a new and useful Drawing Instrument, of which the following is a specication.

This invention has reference to drawing tools, and it refers in particular to a combination of ruling means of different shapes which are guided upon each other, and it is one of the objects of my invention to provide a device of the kind referred to in which any amount of separate ruling means can be combined in such a manner as to be easily adjusted in relation to each other without any necessity of taking them apart for adjustment while at the same time allowing them to be used separately both in the assembled position as well as when taken apart. The device provides a means of as-.

sembling a set of drawing tools of the character described so as to prevent their being accidentally lost when in use, and it also provides means whereby the parts may be easily locked in any adjusted position without interfering with their ready adaptability for the purpose in question.

My invention which is not limited to any particular number and shape of drawing tools of the character described, is shown by way of example on the accompanyingillustration of a draftsmans tool embodying the principles of my invention.

In the drawing Figure 1 is a plan view.

Fig. 2 is a longitudinal section on the line 2 2 of Fig. 1.

Fig. 3 is a cross section on the line 3--3 of Fig. 1.

In the structure shown in the drawing a combination of three ruling tools is shown, 1 representing a square, 2 a sectional arc, being a quarter circle for instance and 3 a straight bar, a ruler or the like. 4: are loop shaped guides secured to the sectional circle 2 by means of which it may be slid along either of the arms of the square 1. 5 is a pointer or indicator on the sectional circle indicating the position of the same with relation to the graduations 1 of the square. One or more guide hooks 7, 8 are provided at suitable points of the ruler 3 for the purpose of guiding it along the sectional arc 2, as well as along either of the arms of the square 1. In order to be able to secure the ruler at different angles with relation to the arms of the square the guide 8 is movable along the ruler 3 so as to be able to vary the distance of the said guide 8 from the adjacent arm'oi the square 1, and in order to prevent disengagement of the said movable guide 8 lfrom the square. 1 during its adjustment which involves rotation about the arc 2V the guide 8 is provided with a laterally or angularly extending lip' 9.

For the purpose oi locking the movable guide8 in any position to which it may be adjusted, there is provided on this guide a cam 10 pivotally mounted, as at 1l, between ears 12 upstanding from the guide 8. The different portions of the ruler may be provided if desired, with graduations,

1, 2', 3 respectively but it is obvious that v the provision of such graduations is not an essential part of my invention. Knobs, pins or the like 6, G may be provided at the ends or at any other points of the straight ruler to assist in the adjustment oi the parts.

In order to limit the movement of the ruler 3, and in order to better retain it in its adjusted position when laying off an angle on the arc 2 stopping or abutting means may be provided on the ruler 3, such as shown for instance at 12 of the drawing. This abutment also serves as a foot to protect the clamps 7 and 9.

The short arm of the square has been found to be of considerable utility in laying out frames and the like containing two right angles. The arc is slidably mounted on the base ot' the square so Vthat it can be brought to any desired distance from the heel of the square when laying out ratter cuts, braces, framing, etc. The arc or segment indicates the angle of the cut or the pitch of a rafter, according to the use to which the tool is placed. For example in laying off a rafter, the slidable arc or segment is slid along the lower member of the square until the pointer or index 5 registers with the graduation indicating the length of the span to be covered by the rafter. The bar 3 is then adjusted angularly until it registers with the graduation on the vertical portion of the square indicating the rise of the rafter. By marking along the bottom and vertical portion of the square the cuts at the ends of the rafter will be indicated. The length of the rafter between cuts will be indicated by the graduatons on the member 3, as will be 'at right angles therefrom, the instrument is placed in proper position on the timber and a line drawn along the edge of the long arm of the square. Another line is then drawn along the short arm of the square at the proper point and then, without removing the square and inverting it, the said square can be slid along the line to the point where the othervline is to be drawn at right angles whereupon said line is drawn along the arm l. This is only one of many advantages resulting from the useV of the arm l.

Having described my invention what I claim is: Y

In a drawing instrument the combination with a graduated square, of a graduated are slidably mounted on one or' the arms of the square, an indicator carried thereby for designating any one of the graduations upon -said arm, a graduated member movably mounted on the are and extending across one face of the square, a guide slidably mounted on said graduated member, a lip projecting rom the guide and lapping the other face of the square, a cam lever carried by the guide and frictionally engaging the graduated member to bind the vlip against the square and to hold the graduated member against movement relative to the square and to hold the guide against movement on the graduated member, means carried by the graduated member for embracing the arc to hold the graduated member and are properly assembled and adjusting knobs extendingirom the end portions of the graduated member. y

In testimony that I claim the foregoing as my own, l have hereto affixed my signature in the presence of two witnesses.

' HORACE L. READ.

l/Vitnesses:

R. B. STEWART, R. A. CHILDERS. Y 

